An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3000 and 6000 m. Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth âs surface. They are among the flattest, smoothest and least explored regions on Earth.
Jim Beckwourth. On this day in 1844, Jim Beckwourth discovered a path through the Sierra Nevada Mountains that now bear his name. Beckwourth Pass on U.S. Alt 40 between Reno, Nevada and Sacramento, California made overland travel to the gold fields of California. Tweet.
His survey placed placed the border from Lake Tahoe to the Colorado River askew with that established by the U.S. Coast and Geodetic Survey between 1893 and 1899, putting Boundary Peak in California. If the USGS had not changed the border, Wheeler Peak in Great Basin National Park, would be Nevada's high point.